Dwell rotor for a distributor



1955 w. F. JAMIESON ETAL DWELL ROTOR FOR A DISTRIBUTOR Filed May 11, 1954 do hm dam/es 0/7 cf? W/7// INVEN TORS 'am Edam/es or,

ATTOIE/VEYJ' United States Patent 2,766,338 W L RQI R F R A DISTRIB William F. Jamieson and John Jamieson, Philadelphia, Pa. Application May 11, 1954, Serial No. 428,946 2 Claims. (Cl. 200-24) This invention relates to an improved dwell rotor distributor for the ignition system of an internal combustion engine.

A main object of the invention is to provide a novel and improved circuit breaking means for breaking the primary circuit of the distributor coil of an automobile ignition system, the improved circuit breaking means being simple in construction, being reliable in operation, and requiring no adjustment.

A further object of the invention is to provide an improved dwell rotor for use with the distributor of an internal combustion engine ignition system to intermittently make and break the primary circuit of the spark coil of the ignition system associated with the distributor, the improved rotor accomplishing the same result as the presently employed distributor points and cam of a conventional distributor, but being considerably less expensive to fabricate, easier to replace, being less affected by wear of the parts of the distributor than the conventional distributor points and cam, and requiring no adjustments, as well as being considerably lower in cost than the conventional distributor points and cam means for operating same presently employed.

Further objects and advantages of the invention will become apparent from the following description and claims, and from the accompanying drawings, wherein:

Figure 1 is a top view of an improved dwell rotor distributor according to the present invention, shown mounted on the top end portion of a distributor shaft.

Figure 2 is a vertical cross sectional view taken on the line 2-2 of Figure 1.

Figure 3 is a top view, similar to Figure 1, with the improved dwell rotor removed.

Figure 4 is a bottom view of the dwell rotor illustrated in Figures 1 and 2.

Referring to the drawings, 11 designates the shaft of a distributor which is operatively driven by an internal combustion engine in a conventional manner and which is conductively grounded to the frame of the engine. Designated at 12 is a generally circular housing having a sleeve portion 13 surrounding the distributor shaft 11, the shaft being freely rotatable relative to the housing 12 and sleeve 13, the shaft being formed with a collar ele- .sent 1 which overlies the horizontal circular wall of the housing 12. The shaft 11 is formed with a reduced top end portion 15.

Designated at 16 is a contact brush which is slidably mounted in a cup member 17 of conductive material, said cup member being provided with a coiled spring 18 hearing between the bottom wall of the cup member and the bottom end of the contact brush 16 and biasing the brush upwardly, as is clearly shown in Figure 2. The cup member 17 is supported on an insulating plate 19 which is secured to the circular wall of housing 12 by bolts 20 and nuts 21 engaged on said bolts. As will be clearly apparent from Figure 2, the brush member 16 extends parallel to the top end portion 15 of the shaft 11 and is spaced outwardly therefrom. The housing 12 2,766,338 Patented Oct, 9, 1956 2 is formed with an upstanding marginal flange 22, and secured in said flange is a terminal 23 which is connected by a wire 24 to the conductive cup member 17 containing the brush 16.

Designated at 25 is a disc rotor of insulating material which is formed with a depending central boss 26, said boss being recessed centrally at 27 and fitting over the reduced top end portion 15 of the distributor shaft 11, as shown in Figure 2. Secured in the recess 27 of the boss 26 is a resilient conductive spring 28 which is wedgingly engaged between the reduced top end portion 15 of shaft 11 and the wall of recess 27 and frictionally secures the rotor 25 to the shaft 11 for rotation therewith.

The resilient spring 28 is formed with the top flange 29 which is connected by a plurality of separate conductors 30 each to a plurality of spaced arcuate contact segments 31 molded in the rotor 25 and exposed at the bottom surface thereof, as shown in Figure 2. The spaced arcuate contact elements 31 are at the same radial distance from the axis of the recess 27 as the brush element 16, whereby said brush element is intermittently engage able with the spaced arcuate contact segments 31 responsive to rotation of the distributor shaft 11. Molded in the bottom surface portion of the rotor 25 between adjacent arcuate contact elements 31 are additional arcuate segments 32 which are not connected in any suitable Way to the ignition circuit, being merely employed to define desired predetermined gaps between adjacent contact segments 31.

The distributor shaft 11 is grounded, whenever the brush .16 engages one of the contact segments 31, the terminal 23 is grounded. The terminal 23 is connected in the conventional manner to an ignition coil (not shown) to intermittently open and close the circuit of the low tension winding of the distributor coil in the same manner as is accomplished by the conventional breaker points.

Secured in the top surface portion of the rotor 25 is the radially extending conductive arm 33 which corresponds to the distributor arm employed on the rotor of a conventional distributor and which serves to distribute the high potential to the respective spark plug electrodes (not shown) as the distributor rotor rotates, as in the conventional distributor.

As will be apparent, the spacing between the successive conductive segments 31 is fixed, and therefore no adjustment of the distributor is necessary, thus avoiding the requirement of adjustment of the distributor points required in the presently employed distributors.

When the contact segments 31 become excessively worn or deteriorated, the rotor may be replaced by merely disengaging same from the reduced top end portion 15 of the distributor shaft and mounting a new rotor thereon.

While a specific embodiment of an improved dwell rotor for a distributor has been disclosed in the foregoing description, it will be understood that various modifications within the spirit of the invention may occur to those skilled in the art. Therefore, it is intended that no limitations be placed on the invention except as defined by the scope of the appended claims.

What is claimed is:

1. In a distributor, a conductive cylindrical housing having a bottom wall and a sidewall, central means on said bottom wall for mounting said housing non-rotatably on a distributor shaft, a single fixed spring pressed contact rising from said bottom wall in radially spaced relation to said central means, said contact being insulated from said housing, a non-conductive disc rotor having means for mounting the same on a distributor shaft within said housing to rotate with the shaft, said rotor having an underside spaced above the housing bottom and overlying said single contact, circumferentially spaced contact segments on the underside of the rotor engageable with said single contact, first conductive means for severally connecting said segments to the distributor shaft.

2. In a distributor, a conductive cylindrical housing having a bottom wall and a sidewall, central means on said bottom wall for mounting said housing non-rotatably on a distributor shaft, a single fixed spring pressed contact rising from said bottom wall in radially spaced relation to said central means, said contact being insulated from said housing, a non-conductive disc rotor having means for mounting the same on a distributor shaft within said housing to rotate with the shaft, said rotor having an underside spaced above the housing bottom and overlying said single contact, circumferentially spaced contact segments on the underside of the rotor engageable with said single contact, first conductive means for severally connecting said segments to the distributor shaft, said rotor having an upper side, and a conductive arm mounted radially upon said upper side and having an outer end projecting radially beyond said rotor.

References Cited in the file of this patent UNITED STATES PATENTS 2,510,067 Callander June 6, 1950 2,574,616 Brown Nov. 13, 1.951

FOREIGN PATENTS 673,920 Great Britain June 11, 1952 

